Fertilizer-induced phosphorus dynamics in alkaline-calcareous soils as influenced by soil chemical properties
Duminda, D. M. S.; Kumaragamage, D.; Indraratne, S.P.; Flaten, D.
Canadian Journal of Soil Science 97(2): 159-170
ISSN/ISBN: 0008-4271 DOI: 10.1139/cjss-2016-0055
For proper fertility management, the influence of soil properties on phosphorus (P) dynamics with fertilizer application should be better understood. We examined the influence of soil chemical properties on P dynamics with the application of monoammonium phosphate (MAP) to alkaline-calcareous soils from Manitoba. Nonfertilized and MAP-fertilized soils (at 30 and 60 kg P ha(-1)) were incubated for 8 wk. At 2 wk intervals, we analyzed pore water samples for dissolved reactive P (DRP) concentration, and soil samples for Olsen P (OP) and Mehlich-3 P (M3P) concentrations. Change in pore water DRP concentration with fertilizer application varied from a slight decrease (-0.02 mg L-1) to a significant, large increase (3.1 mg L-1) and showed a significant, negative relationship with P sorption capacity. The increase in OP and M3P with fertilizer application was influenced by the rate of P applied, initial soil test P and P sorption capacity. The estimated mean OP and M3P to maintain pore water DRP concentration at 0.2 mg L-1 were 25 and 48 mg kg(-1), respectively. Fertilizer application at the same rate resulted in a widely varying degree of P saturation (DPS) increment depending on soil properties, indicating the importance of monitoring DPS changes for sustainable fertilizer use.